I have an ongoing list of games I'm on the lookout for, some are incredibly rare and some are very common. I buy what sounds interesting and fun to me regardless of rarity. Ironically, I've found that most rare games or games that re considered "hidden gems" are vastly inferior to similar games that sold in the millions. I feel like if a rare game is even remotely fun this gives collectors ammo to over hype a game until its price skyrockets. I've seen this happen countless times.
Yet there are also plenty of examples of these games being equal or superior than other cheaper alternatives of certain genre's.
On topic
I never keep lists of rare games It's not really fun it gives the need to hunt for certain titles wich you might probably never get unless your willing to spend.
"plenty" is definitely a stretch, but yes, there are some.
if buy rare you mean at the very least the 50+ range for allot of genre's there are not that many cheap alternatives unless your including compilations modern releases for ps4 etc.
run & gun, shoot em ups action platfomers are some genre's where the best games reside in that expensive range , allot of the cheaper titles with a few exceptions aren't that great or the options are just bare bones.
I agree that in the normal platform games where mario and sonic reside and in the survival horror genre that indeed those common games is the stuff where it's at to name some examples but plenty of genre's where the cheap titles aren't the best not to mention that if were talking about 150 + value games there aren't that many to begin with and from my experience is a solid % wich at least is equal if not better than more common alternatives.
Look at snes and sega plenty of genre's where the best games reside in the more rare or sought after expensive titles. If your going for that 30 $ or less list There are no winners in there except for some mascot games like sonic & mario and some of the common arcade games wich are good but not the best a bit exaterated but were talking about the best games for certain genre's. The choices are limited in my opinion if were talking about the best games for the system.
Everyone has there opinion but from my experience I can't agree that there are only some games that are better than ones that are common plenty of genre's that just don't deliver.
I'm not saying that if a game is slightly better it justifies a sometimes 10 times higher price but if were talking about the best games there is a very solid amount of the rare games wich are in my opinion among the top especially in the 16 bit and 32 bit era. Name me an rpg in that era wich are among the best wich are affordable I'm pretty sure the more affordable ones where the ones with less quality excluding ps1.
And speaking of common games being better than rare games, say the saturn are there actually any cheap good games I mean seriously 
Your not going to tell me that on the saturn the best games are the common ones.
Clock work night, panzer dragoon maybe, but your going to tell me that the saturn has common games wich are superior over the sought after rare ones, for saturn the common library does not even stand a chance the way I see it I must be missing something the more interesting games are in the more expensive price range if I am not mistaken.
On the saturn, rayforce is not only one of the cheapest shmups ( around $30), but also one of the best on the system w/ the tate mode. Same goes for Darius Gaiden.
In japan sure the reason why people import many saves on western expensive games.
But the US and european version of both those games are both a hell lot pricier than 30 very uncommon at the very least.
rayforce named galactic attack in the western parts.
Also the japan versions while cheaper are not the kind of games that have sold millions and could be considered super common, would have been much cheaper if so.
By common I would expect
mario bros, Double dragon, zelda Megaman 2 lvl's of common at the very least wich come with pretty cheap prices when bought as lose carts
